PHYSICS

JEE Physics Formula Sheet

A curated, chapter-wise reference of Physics formulas, optimized for JEE Mains & Advanced preparation. Download printable PDF sheets for offline study.

Exam suite:

1. Units & Measurement

Units and Systems of Units

SI and CGS Conversion Relations

M A
1 N=105 dyn1 \text{ N} = 10^5 \text{ dyn}
1 J=107 erg1 \text{ J} = 10^7 \text{ erg}
Parameters & Definitions

N is Newton, dyn is dyne, J is Joule, and erg is erg.

Physical conversions for force (Newton to dyne) and energy (Joules to ergs) between SI and CGS systems.

Dimensional Representation

General Dimensional Representation

M A
[Q]=MaLbTcIdθeNfJg[Q] = M^a L^b T^c I^d \theta^e N^f J^g
Parameters & Definitions

[Q][Q] represents the dimensions of physical quantity QQ; M,L,T,I,θ,N,JM, L, T, I, \theta, N, J are the seven fundamental dimensions.

Expressing any physical quantity in terms of base dimensions (Mass, Length, Time, etc.).

Absolute and Relative Errors

Mean Absolute Error

M A
amean=1ni=1naia_{mean} = \frac{1}{n} \sum_{i=1}^n a_i
Δamean=1ni=1nameanai\Delta a_{mean} = \frac{1}{n} \sum_{i=1}^n |a_{mean} - a_i|
Parameters & Definitions

aia_i is the ii-th measurement, ameana_{mean} is the arithmetic mean, and Δamean\Delta a_{mean} is the mean absolute error.

The mean of the absolute values of the differences between individual measurements and the true mean value.

Relative and Percentage Error

M A
er=Δameanameane_r = \frac{\Delta a_{mean}}{a_{mean}}
ep=Δameanamean×100%e_p = \frac{\Delta a_{mean}}{a_{mean}} \times 100\%
Parameters & Definitions

ere_r represents relative error, and epe_p represents percentage error.

Relative error is the fractional value of absolute error relative to the mean, and percentage error is its value expressed as a percentage.

Propagation of Errors

Propagation of Errors in Calculations

M A
Z=A±B    ΔZ=ΔA+ΔBZ = A \pm B \implies \Delta Z = \Delta A + \Delta B
Z=ApBqCr    ΔZZ=pΔAA+qΔBB+rΔCCZ = A^p B^q C^{-r} \implies \frac{\Delta Z}{Z} = p \frac{\Delta A}{A} + q \frac{\Delta B}{B} + r \frac{\Delta C}{C}
Parameters & Definitions

A,B,CA, B, C are measured quantities with errors ΔA,ΔB,ΔC\Delta A, \Delta B, \Delta C; ZZ is the resulting calculated quantity.

Formulas to calculate the maximum absolute and relative errors propagated through arithmetic combinations.

2. Motion in a Straight Line

Frame of Reference & Displacement

Average Speed and Velocity Inequality

M A
vavg=Total DistanceTotal Timev_{avg} = \frac{\text{Total Distance}}{\text{Total Time}}
vavg=ΔrΔt    vavgvavg\vec{v}_{avg} = \frac{\Delta \vec{r}}{\Delta t} \implies |\vec{v}_{avg}| \le v_{avg}
Parameters & Definitions

vavgv_{avg} is average speed, vavg\vec{v}_{avg} is average velocity vector, Δr\Delta \vec{r} is displacement vector, and Δt\Delta t is total elapsed time.

Defines average speed and average velocity vector, establishing that the magnitude of average velocity is always less than or equal to average speed.

Average & Instantaneous Velocity

Average and Instantaneous Velocity

M A
vavg=ΔxΔtv_{avg} = \frac{\Delta x}{\Delta t}
vinst=dxdtv_{inst} = \frac{dx}{dt}
Parameters & Definitions

vavgv_{avg} is the average velocity, vinstv_{inst} is the instantaneous velocity, xx represents position, and tt represents time.

Average velocity is displacement divided by time interval, while instantaneous velocity is the time derivative of position.

Equations of Motion

Equations of Motion for Uniform Acceleration

M A
v=u+atv = u + at
s=ut+12at2s = ut + \frac{1}{2}at^2
v2u2=2asv^2 - u^2 = 2as
sn=u+a2(2n1)s_n = u + \frac{a}{2}(2n - 1)
Parameters & Definitions

uu is initial velocity, vv is final velocity, aa is constant acceleration, tt is elapsed time, ss is displacement, and sns_n is the displacement in the nn-th second.

Relationships between velocity, displacement, time, and acceleration for constant acceleration.

Relative Velocity in 1D

Relative Velocity in One Dimension

M A
vAB=vAvBv_{AB} = v_A - v_B
Parameters & Definitions

vABv_{AB} is the velocity of object A relative to B, vAv_A is the velocity of A, and vBv_B is the velocity of B.

The velocity of an object A as observed from the reference frame of an object B.

3. Motion in a Plane

Vector Operations

Parallelogram Law of Vector Addition

M A
R=A2+B2+2ABcosθR = \sqrt{A^2 + B^2 + 2AB\cos\theta}
tanα=BsinθA+Bcosθ\tan\alpha = \frac{B\sin\theta}{A + B\cos\theta}
Parameters & Definitions

RR is magnitude of resultant vector, A,BA, B are magnitudes of the individual vectors, θ\theta is angle between them, and α\alpha is angle of resultant with vector AA.

Calculates the magnitude and direction of the resultant vector of two vectors added at angle θ\theta.

Dot and Cross Products

Dot and Cross Products of Vectors

M A
AB=ABcosθ\vec{A} \cdot \vec{B} = AB \cos\theta
A×B=ABsinθ|\vec{A} \times \vec{B}| = AB \sin\theta
Parameters & Definitions

A\vec{A} and B\vec{B} are vectors, AA and BB are their magnitudes, and θ\theta is the angle between them.

Mathematical representations of scalar (dot) and vector (cross) products of two vectors.

Projectile Motion

Formulas for Projectile Motion under Gravity

M A
T=2usinθgT = \frac{2u \sin\theta}{g}
H=u2sin2θ2gH = \frac{u^2 \sin^2\theta}{2g}
R=u2sin2θgR = \frac{u^2 \sin 2\theta}{g}
y=xtanθgx22u2cos2θy = x \tan\theta - \frac{gx^2}{2u^2 \cos^2\theta}
Parameters & Definitions

uu is the launch speed, θ\theta is the launch angle with the horizontal, TT is time of flight, HH is max height, RR is range, and gg is acceleration due to gravity.

Time of flight, maximum height, horizontal range, and the equation of the trajectory for a projectile launched from ground level.

Uniform Circular Motion

Centripetal Acceleration and Angular Velocity Relations

M A
v=ωrv = \omega r
ω=2πf=2πT\omega = 2\pi f = \frac{2\pi}{T}
ac=v2r=ω2ra_c = \frac{v^2}{r} = \omega^2 r
Parameters & Definitions

vv is linear speed, ω\omega is angular velocity, rr is circular radius, ff is frequency, TT is time period, and aca_c is centripetal acceleration.

Relations linking linear speed, angular velocity, frequency, and centripetal acceleration in uniform circular motion.

4. Laws of Motion

Forces & Newton's Laws

Newton's Second Law

M A
F=dpdt=ma\vec{F} = \frac{d\vec{p}}{dt} = m\vec{a}
Parameters & Definitions

F\vec{F} is force, p\vec{p} is linear momentum, mm is mass, and a\vec{a} is acceleration.

Definition of force as the rate of change of linear momentum.

Momentum & Impulse

Momentum and Impulse

M A
p=mv\vec{p} = m\vec{v}
J=Fdt=Δp\vec{J} = \int \vec{F} dt = \Delta \vec{p}
Parameters & Definitions

p\vec{p} is linear momentum, mm is mass, v\vec{v} is velocity, J\vec{J} is impulse, and Δp\Delta \vec{p} is the change in momentum.

Definition of momentum and impulse as the change in momentum.

Friction Forces

Static and Kinetic Friction Limits

M A
fs,max=μsNf_{s,max} = \mu_s N
fk=μkNf_k = \mu_k N
Parameters & Definitions

fs,maxf_{s,max} is limiting static friction, fkf_k is kinetic friction, μs\mu_s and μk\mu_k are coefficients of static and kinetic friction respectively, and NN is normal force.

Formulas to calculate maximum static friction and kinetic friction.

Circular Roads & Banking

Critical Speeds on Level and Banked Circular Roads

M A
vlevel=μsrgv_{level} = \sqrt{\mu_s rg}
vopt=rgtanθv_{opt} = \sqrt{rg \tan\theta}
vmax=rg(μs+tanθ1μstanθ)v_{max} = \sqrt{rg \left( \frac{\mu_s + \tan\theta}{1 - \mu_s \tan\theta} \right)}
Parameters & Definitions

rr is circular radius, gg is acceleration due to gravity, μs\mu_s is coefficient of static friction, θ\theta is banking angle, voptv_{opt} is friction-free optimum speed, and vmaxv_{max} is maximum safe speed.

Formulas for maximum safe speed on flat and banked roads.

5. Work, Energy & Power

Work Done by Forces

Work Done by Forces

M A
W=FdW = \vec{F} \cdot \vec{d}
W=FdrW = \int \vec{F} \cdot d\vec{r}
Parameters & Definitions

WW is work done, F\vec{F} is force, d\vec{d} is constant displacement, and drd\vec{r} is differential displacement.

Definition of work done by constant and variable forces.

Kinetic Energy & Work-Energy Theorem

Work-Energy Theorem and Power

M A
Wnet=ΔK=KfKiW_{net} = \Delta K = K_f - K_i
P=dWdt=FvP = \frac{dW}{dt} = \vec{F} \cdot \vec{v}
Parameters & Definitions

WnetW_{net} is net work done, ΔK\Delta K is change in kinetic energy, PP is power, F\vec{F} is force, and v\vec{v} is velocity.

The work-energy theorem (net work equals change in kinetic energy) and instantaneous power.

Conservative Forces

Relation Between Force and Potential Energy

M A
Fx=dUdxF_x = -\frac{dU}{dx}
Parameters & Definitions

FxF_x is the conservative force along the x-axis, and UU is the potential energy as a function of position xx.

Formula relating a conservative force to the spatial gradient of its potential energy.

Spring Potential Energy

Potential Energy of a Hookean Spring

M A
U=12kx2U = \frac{1}{2} k x^2
Parameters & Definitions

UU is the stored potential energy, kk is the spring constant, and xx is the extension or compression.

Potential energy stored in a spring stretched or compressed by an displacement xx.

Vertical Circular Motion

Critical Speeds in Vertical Circular Motion

M A
vlowest=5gRv_{\text{lowest}} = \sqrt{5gR}
vhighest=gRv_{\text{highest}} = \sqrt{gR}
TlowestThighest=6mgT_{\text{lowest}} - T_{\text{highest}} = 6mg
Parameters & Definitions

vv is the critical speed, TT is the tension in the string, RR is the radius of the circle, mm is the mass, and gg is the acceleration due to gravity.

Minimum speeds required at the lowest and highest points for a mass on a string to complete a vertical circle.

Collisions & Restitution

Coefficient of Restitution and Collision Speeds

M A
e=v2v1u1u2e = \frac{v_2 - v_1}{u_1 - u_2}
v1=(m1em2m1+m2)u1+((1+e)m2m1+m2)u2v_1 = \left( \frac{m_1 - e m_2}{m_1 + m_2} \right) u_1 + \left( \frac{(1+e) m_2}{m_1 + m_2} \right) u_2
Parameters & Definitions

ee is the coefficient of restitution, u1,u2u_1, u_2 are velocities before collision, v1,v2v_1, v_2 are velocities after collision, and m1,m2m_1, m_2 are the colliding masses.

Definition of coefficient of restitution (ee) and final velocities after a 1D elastic or inelastic collision.

6. Rotational Motion

Centre of Mass of Particle Systems

Position of Centre of Mass

M A
rcm=mirimi\vec{r}_{cm} = \frac{\sum m_i \vec{r}_i}{\sum m_i}
Parameters & Definitions

rcm\vec{r}_{cm} is the center of mass position vector, and mim_i and ri\vec{r}_i are the mass and position of the ii-th particle.

Weighted average position of a discrete system of particles.

Centre of Mass of Rigid Bodies

Centre of Mass for Continuous Media

M A
rcm=1Mrdm\vec{r}_{cm} = \frac{1}{M} \int \vec{r} dm
Parameters & Definitions

rcm\vec{r}_{cm} is the center of mass position vector, MM is total mass, and dmdm is a differential mass element.

Weighted average position for a continuous mass distribution.

Torque and Equilibrium

Torque and Angular Acceleration Relation

M A
τ=r×F=Iα\vec{\tau} = \vec{r} \times \vec{F} = I\vec{\alpha}
Parameters & Definitions

τ\vec{\tau} is torque, r\vec{r} is position vector, F\vec{F} is force vector, II is moment of inertia, and α\vec{\alpha} is angular acceleration.

Definition of torque and the relation linking net torque to angular acceleration.

Angular Momentum

Angular Momentum and Net Torque

M A
L=r×p=Iω\vec{L} = \vec{r} \times \vec{p} = I\vec{\omega}
τnet=dLdt\vec{\tau}_{net} = \frac{d\vec{L}}{dt}
Parameters & Definitions

L\vec{L} is angular momentum, r\vec{r} is position, p\vec{p} is linear momentum, II is moment of inertia, ω\vec{\omega} is angular velocity, and τnet\vec{\tau}_{net} is net torque.

Definition of angular momentum and the relation linking net torque to the rate of change of angular momentum.

Moment of Inertia & Radius of Gyration

Moment of Inertia and Radius of Gyration

M A
I=miri2=r2dmI = \sum m_i r_i^2 = \int r^2 dm
I=MK2I = MK^2
Parameters & Definitions

II is moment of inertia, rr represents distance from axis of rotation, MM is total mass, and KK is the radius of gyration.

General definition of moment of inertia and its relation to the radius of gyration.

Axes Theorems

Parallel and Perpendicular Axes Theorems

M A
Iz=Icm+Md2I_z = I_{cm} + Md^2
Iz=Ix+IyI_z = I_x + I_y
Parameters & Definitions

IzI_z is moment of inertia about the target axis, IcmI_{cm} is moment of inertia about parallel center-of-mass axis, MM is total mass, dd is perpendicular distance between axes, and Ix,IyI_x, I_y are moments of inertia about perpendicular axes in the plane of a laminar sheet.

Mathematical expressions of the parallel axes theorem and perpendicular axes theorem for moments of inertia.

7. Gravitation

Kepler's Laws & Newton's Law

Universal Gravitational Force and Kepler's Third Law

M A
F=Gm1m2r2F = G \frac{m_1 m_2}{r^2}
T2=(4π2GMs)r3T^2 = \left( \frac{4\pi^2}{GM_s} \right) r^3
Parameters & Definitions

FF is gravitational force, GG is gravitational constant, m1,m2m_1, m_2 are masses, rr is orbital radius, TT is orbital period, and MsM_s is mass of the central star/Sun.

Newton's force equation for gravity and the mathematical relation for Kepler's third law of planetary motion.

Gravity (g) and its Variations

Variation of g with Altitude, Depth, and Rotation

M A
ghg(12hR)g_h \approx g \left( 1 - \frac{2h}{R} \right)
gd=g(1dR)g_d = g \left( 1 - \frac{d}{R} \right)
g=gω2Rcos2ϕg' = g - \omega^2 R \cos^2\phi
Parameters & Definitions

gg is gravity at sea level, ghg_h and gdg_d are gravity values at height hh and depth dd, RR is Earth's radius, ω\omega is Earth's rotational speed, and ϕ\phi is the latitude.

Formulas calculating how earth's gravitational acceleration changes at heights (hRh \ll R), depths (dd), and latitudes (ϕ\phi).

Gravitational Potential & Energy

Gravitational Potential Energy and Potential

M A
U=GMmrU = -G \frac{M m}{r}
V=GMrV = -G \frac{M}{r}
Parameters & Definitions

UU is gravitational potential energy, VV is gravitational potential, M,mM, m are masses, and rr is the separation distance.

Potential energy of a two-mass system and the potential due to a point mass.

Orbital & Escape Velocities

Escape Velocity and Satellite Orbital Velocity

M A
ve=2GMR=2gRv_e = \sqrt{\frac{2GM}{R}} = \sqrt{2gR}
vo=GMR=gRv_o = \sqrt{\frac{GM}{R}} = \sqrt{gR}
Parameters & Definitions

vev_e is escape velocity, vov_o is orbital velocity, MM is Earth's mass, RR is Earth's radius, and gg is acceleration due to gravity.

Formulas to calculate escape speed from Earth and the speed required for circular orbit close to Earth.

8. Elasticity

Stress & Strain

Hooke's Law of Elasticity

M A
Stress=E×Strain    FA=EΔLL0\text{Stress} = E \times \text{Strain} \implies \frac{F}{A} = E \frac{\Delta L}{L_0}
Parameters & Definitions

FF is applied deforming force, AA is cross-sectional area, EE is modulus of elasticity, ΔL\Delta L is elongation, and L0L_0 is original length.

Fundamental linear relationship of elasticity indicating stress is directly proportional to strain within the elastic limit.

Elastic Moduli

Young's and Bulk Moduli

M A
Y=FLAΔLY = \frac{F L}{A \Delta L}
B=ΔPΔV/VB = -\frac{\Delta P}{\Delta V / V}
Parameters & Definitions

YY is Young's Modulus, BB is Bulk Modulus, FF is stretching force, LL is length, AA is area, ΔL\Delta L is extension, ΔP\Delta P is pressure change, and ΔV\Delta V is volume change.

Definitions of Young's and Bulk Moduli of elasticity.

Poisson's Ratio and Elastic Constants Relations

M A
σ=Lateral StrainLongitudinal Strain=Δd/d0ΔL/L0\sigma = \frac{\text{Lateral Strain}}{\text{Longitudinal Strain}} = -\frac{\Delta d / d_0}{\Delta L / L_0}
Y=3B(12σ)=2η(1+σ)Y = 3B(1 - 2\sigma) = 2\eta(1 + \sigma)
9Y=1B+3η\frac{9}{Y} = \frac{1}{B} + \frac{3}{\eta}
Parameters & Definitions

σ\sigma is Poisson's ratio (theoretical limits: 1σ0.5-1 \le \sigma \le 0.5), YY is Young's modulus, BB is Bulk modulus, and η\eta is Shear modulus (rigidity modulus).

Defines Poisson's ratio and the fundamental mathematical relations between Young's, Bulk, and Shear moduli.

Elastic Energy Density

Elastic Strain Energy Density

M A
uenergy=12×Stress×Strainu_{energy} = \frac{1}{2} \times \text{Stress} \times \text{Strain}
Parameters & Definitions

uenergyu_{energy} is energy density, Stress represents applied force per unit area, and Strain is fractional deformation.

The elastic strain energy stored per unit volume of a stretched body.

9. Fluid Mechanics

Hydrostatic Pressure

Hydrostatic Pressure variation

M A
P=P0+ρghP = P_0 + \rho g h
Parameters & Definitions

PP is total pressure at depth hh, P0P_0 is atmospheric pressure at surface, ρ\rho is fluid density, and gg is acceleration due to gravity.

Formula for pressure at depth hh in a fluid of density ρ\rho.

Buoyancy & Archimedes Principle

Buoyant Force (Archimedes' Principle)

M A
FB=ρfVsubgF_B = \rho_f V_{\text{sub}} g
Parameters & Definitions

FBF_B is the buoyant force, ρf\rho_f is the density of the fluid, VsubV_{\text{sub}} is the volume of the submerged part of the body, and gg is the acceleration due to gravity.

Formula to calculate the upward buoyant force acting on a body fully or partially submerged in a fluid.

Viscosity & Stokes' Law

Stokes' Law and Terminal Velocity

M A
Fd=6πηrvF_d = 6\pi \eta r v
vt=29r2(ρbodyρfluid)gηv_t = \frac{2}{9} \frac{r^2(\rho_{body} - \rho_{fluid})g}{\eta}
Parameters & Definitions

FdF_d is viscous drag, η\eta is coefficient of viscosity, rr is sphere radius, vv is speed, vtv_t is terminal velocity, ρbody\rho_{body} is density of sphere, and ρfluid\rho_{fluid} is fluid density.

Viscous drag force on a sphere and its ultimate terminal speed through a viscous medium.

Streamline & Turbulent Flow

Reynolds Number Flow Regime

M A
Re=ρvdη    {Re<1000Laminar FlowRe>2000Turbulent FlowR_e = \frac{\rho v d}{\eta} \implies \begin{cases} R_e < 1000 & \text{Laminar Flow} \\ R_e > 2000 & \text{Turbulent Flow} \end{cases}
Parameters & Definitions

ReR_e is Reynolds number, ρ\rho is fluid density, vv is flow velocity, dd is diameter of tube, and η\eta is coefficient of viscosity.

Dimensionless quantity determining whether fluid flow is laminar (streamline) or turbulent.

Bernoulli's Principle & Continuity

Equation of Continuity and Bernoulli's Theorem

M A
A1v1=A2v2A_1 v_1 = A_2 v_2
P+12ρv2+ρgh=constantP + \frac{1}{2}\rho v^2 + \rho g h = \text{constant}
Parameters & Definitions

AA represents cross-sectional area, vv represents flow velocity, PP is pressure, hh is height, and ρ\rho is fluid density.

Conservation of mass and mechanical energy principles in streamline fluid flow.

10. Surface Tension

Surface Energy & Surface Tension

Relation Between Surface Tension and Surface Energy

M A
W=TΔAW = T \cdot \Delta A
Parameters & Definitions

WW is the work done (stored as surface energy), TT is the surface tension of the liquid, and ΔA\Delta A is the increase in surface area (taking both surfaces into account for a film).

Formula for the work done in increasing the surface area of a liquid film.

Excess Pressure

Excess Pressure in Drops/Bubbles

M A
ΔPdrop=2TR\Delta P_{drop} = \frac{2T}{R}
ΔPbubble=4TR\Delta P_{bubble} = \frac{4T}{R}
Parameters & Definitions

TT is surface tension, RR is radius of curved interface, and ΔP\Delta P is the excess pressure.

Formulas calculating excess internal pressure in curved interfaces.

Capillary Rise

Height of Capillary Rise

M A
h=2Tcosθρgrh = \frac{2T \cos\theta}{\rho g r}
Parameters & Definitions

TT is surface tension, hh is capillary height, θ\theta is contact angle, ρ\rho is density of liquid, gg is acceleration due to gravity, and rr is tube radius.

Formula calculating height of capillary liquid column.

11. Thermal Properties

Heat & Temperature Scale

Temperature Scale Conversions

M A
C5=F329=K273.155\frac{C}{5} = \frac{F-32}{9} = \frac{K-273.15}{5}
Parameters & Definitions

CC is temperature in degrees Celsius, FF is in degrees Fahrenheit, and KK is in Kelvin.

Formula to convert temperatures between Celsius, Fahrenheit, and Kelvin scales.

Thermal Expansion

Linear Expansion

M A
L=L0(1+αΔT)L = L_0 (1 + \alpha \Delta T)
Parameters & Definitions

LL is final length, L0L_0 is initial length, α\alpha is linear expansion coefficient, and ΔT\Delta T is temperature change.

Formula for linear dimension changes with temperature.

Specific Heat & Calorimetry

Specific Heat Capacity and Latent Heat

M A
Qheat=msΔTQ_{heat} = m s \Delta T
Qlatent=mLQ_{latent} = m L
Parameters & Definitions

QQ is heat exchanged, mm is mass, ss is specific heat, LL is latent heat, and ΔT\Delta T is temperature change.

Basic heat transfer calculations for temperature and phase changes.

12. Heat Transfer

Conduction & Conductivity

Conduction Rate

M A
dQdt=kA(ThotTcold)L\frac{dQ}{dt} = \frac{kA(T_{hot} - T_{cold})}{L}
Parameters & Definitions

kk is thermal conductivity, AA is area, LL is length, and TT is temperature.

Formula for conductive heat current through a material.

Convection & Radiation

Wien's Displacement Law

M A
λmaxT=b\lambda_{\text{max}} T = b
Parameters & Definitions

λmax\lambda_{\text{max}} is wavelength of maximum radiation intensity, TT is absolute temperature, and bb is Wien's displacement constant (2.898×103 m K2.898 \times 10^{-3} \text{ m K}).

Relates the peak wavelength of blackbody radiation to the absolute temperature of the body.

Black Body Radiation, Stefan & Wien Laws

Stefan's Law and Wien's Law

M A
E=σeAT4E = \sigma e A T^4
λmT=b\lambda_m T = b
Parameters & Definitions

EE is radiative power, σ\sigma is Stefan-Boltzmann constant, ee is emissivity, AA is area, TT is temperature, λm\lambda_m is peak wavelength, and bb is Wien's constant.

Formulas for total radiative power of a blackbody and wavelength of maximum emission.

Newton's Law of Cooling

Newton's Law of Cooling

A
dTdt=K(TTs)\frac{dT}{dt} = -K(T - T_s)
Parameters & Definitions

TT is body temperature, TsT_s is surrounding temperature, KK is positive constant, and tt is time.

Approximate rate of temperature fall of a hot body to its surroundings.

13. Thermodynamics

Thermal Equilibrium & Zeroth Law

Temperature Scale Conversions

M A
TC100=TF32180=TK273.15100\frac{T_C}{100} = \frac{T_F - 32}{180} = \frac{T_K - 273.15}{100}
Parameters & Definitions

TCT_C is Celsius temperature, TFT_F is Fahrenheit temperature, and TKT_K is Kelvin (absolute) temperature.

Conversion equations among Celsius, Fahrenheit, and Kelvin temperature scales.

First Law of Thermodynamics

First Law Equation

M A
ΔQ=ΔU+W\Delta Q = \Delta U + W
Parameters & Definitions

ΔQ\Delta Q is heat added, ΔU=nCvΔT\Delta U = n C_v \Delta T is internal energy change, and WW is work.

Energy conservation equation for thermodynamic systems.

Isothermal & Adiabatic Processes

Work in Isothermal & Adiabatic Processes

M A
Wiso=nRTln(VfVi)W_{iso} = nRT \ln\left(\frac{V_f}{V_i}\right)
Wadi=PiViPfVfγ1W_{adi} = \frac{P_i V_i - P_f V_f}{\gamma - 1}
Parameters & Definitions

WW is work, nn is mole count, RR is gas constant, TT is temperature, Vi,VfV_i, V_f are volumes, Pi,PfP_i, P_f are pressures, and γ\gamma is adiabatic index.

Work formulas for key thermodynamic paths.

Adiabatic State Equations (Poisson's Relations)

M A
PVγ=constantP V^\gamma = \text{constant}
TVγ1=constantT V^{\gamma-1} = \text{constant}
P1γTγ=constantP^{1-\gamma} T^\gamma = \text{constant}
Parameters & Definitions

PP is pressure, VV is volume, TT is absolute temperature, and γ=Cp/Cv\gamma = C_p/C_v is the adiabatic index (ratio of specific heats).

Governing state relations for a quasi-static adiabatic process of an ideal gas.

Second Law of Thermodynamics

Refrigerator Coefficient of Performance (COP)

M A
β=QCW=TCTHTC\beta = \frac{Q_C}{W} = \frac{T_C}{T_H - T_C}
Parameters & Definitions

β\beta is coefficient of performance, QCQ_C is heat extracted from cold reservoir, WW is work input, TCT_C is cold temperature, and THT_H is hot temperature.

Measures the efficiency (COP) of an ideal Carnot refrigerator.

Carnot Engine & Refrigerator

Carnot Engine and Refrigerator performance

A
η=1TCTH\eta = 1 - \frac{T_C}{T_H}
βCOP=TCTHTC\beta_{COP} = \frac{T_C}{T_H - T_C}
Parameters & Definitions

η\eta is efficiency, βCOP\beta_{COP} is coefficient of performance, TCT_C is absolute cold reservoir temperature, and THT_H is absolute hot reservoir temperature.

Efficiency of a Carnot cycle engine and the coefficient of performance of a refrigerator.

14. Kinetic Theory

State Equations & Work

Equation of State and Compression Work

M A
PV=nRTPV = nRT
W=ViVfPextdVW = -\int_{V_i}^{V_f} P_{ext} dV
Parameters & Definitions

PP is pressure, VV is volume, nn is moles, TT is temperature, RR is gas constant, and WW is work done on the gas.

Relation linking pressure, volume, temperature, and moles, and the general work integral for compression.

Assumptions & Pressure Concept

Kinetic Model Pressure

M A
P=13ρvrms2P = \frac{1}{3} \rho v_{rms}^2
Parameters & Definitions

PP is pressure, ρ\rho is density, and vrmsv_{rms} is RMS molecular speed.

Concept of pressure based on kinetic theory of gases.

Molecular Speeds & Degrees of Freedom

Molecular Speeds and Specific Heats

M A
vrms=3RTM=3kBTmv_{rms} = \sqrt{\frac{3RT}{M}} = \sqrt{\frac{3k_B T}{m}}
Cv=f2RCp=(f2+1)RC_v = \frac{f}{2}R \quad C_p = \left(\frac{f}{2} + 1\right)R
Parameters & Definitions

vrmsv_{rms} is RMS speed, MM is molar mass, mm is single molecule mass, kBk_B is Boltzmann constant, Cv,CpC_v, C_p are specific heats, ff is degrees of freedom, and RR is gas constant.

Expressions for RMS velocity and molar heat capacities based on degrees of freedom.

Mean Free Path

Mean Free Path

M A
λ=12πd2n\lambda = \frac{1}{\sqrt{2}\pi d^2 n}
Parameters & Definitions

λ\lambda is mean free path, dd is collision diameter, and nn is number density.

The average distance traveled by a moving gas molecule between successive collisions.

15. Oscillations

Periodic Motion & SHM Basic Equation

Displacement, Velocity and Acceleration in SHM

M A
x(t)=Asin(ωt+ϕ)x(t) = A \sin(\omega t + \phi)
v(x)=ωA2x2v(x) = \omega \sqrt{A^2 - x^2}
a(x)=ω2xa(x) = -\omega^2 x
Parameters & Definitions

xx is displacement, AA is amplitude, ω\omega is angular frequency, ϕ\phi is initial phase, vv is velocity, and aa is acceleration.

Kinematic equations describing standard simple harmonic motion.

Phase & Energy in SHM

Energy in SHM

M A
Etotal=12mω2A2E_{total} = \frac{1}{2} m \omega^2 A^2
Parameters & Definitions

EtotalE_{total} is energy, mm is mass, ω\omega is angular frequency, and AA is amplitude.

Total mechanical energy of SHM.

Spring & Pendulum Periods

Periods of Standard Oscillators

M A
Tspring=2πmkT_{spring} = 2\pi \sqrt{\frac{m}{k}}
Tpend=2πLgT_{pend} = 2\pi \sqrt{\frac{L}{g}}
Parameters & Definitions

TT is time period, kk is spring constant, mm is mass, LL is pendulum length, and gg is acceleration due to gravity.

Time period formulas for springs and pendulums.

Damped & Forced Oscillations

Amplitude Decay in Damped SHM

A
A(t)=A0ebt2mA(t) = A_0 e^{-\frac{b t}{2m}}
ω=ω02(b2m)2\omega' = \sqrt{\omega_0^2 - \left(\frac{b}{2m}\right)^2}
Parameters & Definitions

A(t)A(t) is damped amplitude, A0A_0 is initial amplitude, bb is damping constant, mm is mass, and ω\omega' is the damped angular frequency.

Expression showing exponential decay of amplitude over time in a weakly damped system.

16. Waves

Longitudinal & Transverse Waves

Speed of Wave on String and in Gas

M A
vstring=Tμv_{\text{string}} = \sqrt{\frac{T}{\mu}}
vgas=γRTMv_{\text{gas}} = \sqrt{\frac{\gamma R T}{M}}
Parameters & Definitions

TT is tension, μ\mu is linear mass density, γ\gamma is adiabatic index, RR is gas constant, TT is temperature, and MM is molar mass.

Determines the velocity of transverse waves on a stretched string, and longitudinal sound waves in a gas.

Progressive Waves & Speed

Progressive Wave Equation and String/Gas Wave Speeds

M A
y(x,t)=Asin(kxωt)y(x,t) = A \sin(kx - \omega t)
vstring=Tμv_{string} = \sqrt{\frac{T}{\mu}}
vgas=γRTMv_{gas} = \sqrt{\frac{\gamma R T}{M}}
Parameters & Definitions

yy is displacement, AA is amplitude, k=2π/λk = 2\pi/\lambda is wave number, ω=2πf\omega = 2\pi f is angular frequency, vv represents speed, TT is tension, μ\mu is linear mass density, and γ\gamma is adiabatic index of gas.

Equation of a harmonic progressive wave and formulas for transverse wave speed on a string and longitudinal wave in gases.

Superposition & Reflection

Equation of a Standing Wave

M A
y=2Asin(kx)cos(ωt)y = 2A \sin(kx) \cos(\omega t)
Parameters & Definitions

yy is the displacement at position xx and time tt, AA is the amplitude of individual waves, k=2π/λk = 2\pi/\lambda is the wave number, and ω=2πf\omega = 2\pi f is the angular frequency.

Mathematical representation of a stationary wave formed by the superposition of two identical travelling waves in opposite directions.

Standing Waves & Harmonics

Harmonics in Organ Pipes

M A
fopen=v2Lf_{open} = \frac{v}{2L}
fclosed=v4Lf_{closed} = \frac{v}{4L}
Parameters & Definitions

ff represents frequency, vv is sound velocity, and LL is length of pipe.

Fundamental frequencies of open and closed organ pipes.

Beats

Beat Frequency

M A
fbeat=f1f2f_{beat} = |f_1 - f_2|
Parameters & Definitions

fbeatf_{beat} is beat frequency, and f1,f2f_1, f_2 are source frequencies.

Formula to calculate the beat frequency from two close source frequencies.

Doppler Effect in Sound

General Doppler Shift Formula in Sound

A
f=f(v±vovvs)f' = f \left( \frac{v \pm v_o}{v \mp v_s} \right)
Parameters & Definitions

ff' is observed frequency, ff is source frequency, vv is speed of sound in medium, vov_o is observer speed, and vsv_s is source speed.

Formula for observed frequency when observer and source are in relative motion along line of sight.

17. Electric Charges & Fields

Electric Charges

Quantization of Electric Charge

M A
q=neq = n e
Parameters & Definitions

qq is the net charge, nn is any integer (positive or negative), and e1.6×1019e \approx 1.6 \times 10^{-19} C is the elementary charge of an electron.

Formula expressing that the total charge on a body is an integral multiple of the basic unit of charge.

Coulomb's Law & Superposition

Coulomb's Law of Electrostatic Force

M A
F=14πε0q1q2r2r^\vec{F} = \frac{1}{4\pi\varepsilon_0} \frac{q_1 q_2}{r^2} \hat{r}
Parameters & Definitions

F\vec{F} is force, q1,q2q_1, q_2 are point charges, rr is separation distance, r^\hat{r} is unit vector along separation line, and ε0\varepsilon_0 is vacuum permittivity.

Electrostatic force vector acting between two point charges separated in vacuum.

Electric Fields

Electric Field of a Point Charge

M A
E=14πε0qr2E = \frac{1}{4\pi\varepsilon_0} \frac{q}{r^2}
Parameters & Definitions

EE is electric field intensity, qq is charge magnitude, rr is distance, and ε0\varepsilon_0 is permittivity of free space.

Calculates the magnitude of the electrostatic field produced by a point charge in vacuum.

Electric Dipoles & Torque

Electric Dipole Fields and Torque

M A
Eaxial14πε02pr3E_{axial} \approx \frac{1}{4\pi\varepsilon_0} \frac{2p}{r^3}
Eequatorial14πε0pr3E_{equatorial} \approx \frac{1}{4\pi\varepsilon_0} \frac{p}{r^3}
τ=p×E\vec{\tau} = \vec{p} \times \vec{E}
Parameters & Definitions

p=q(2a)p = q(2a) is electric dipole moment magnitude, rr is distance from dipole center (rar \gg a), EE is electric field, and τ\vec{\tau} is torque vector in field E\vec{E}.

Electric fields at axial/equatorial positions and torque experienced in a uniform external field.

Electric Flux & Gauss Law

Gauss's Law and Electrostatic Field Applications

M A
ΦE=EdA=qenε0\Phi_E = \oint \vec{E} \cdot d\vec{A} = \frac{q_{en}}{\varepsilon_0}
Ewire=λ2πε0rE_{wire} = \frac{\lambda}{2\pi\varepsilon_0 r}
Esheet=σ2ε0E_{sheet} = \frac{\sigma}{2\varepsilon_0}
Parameters & Definitions

ΦE\Phi_E is electric flux, qenq_{en} is enclosed net charge, λ\lambda is linear charge density, σ\sigma is surface charge density, and rr is radial distance.

Integral definition of flux and fields due to standard charge distributions.

18. Electrostatic Potential & Capacitance

Electric Potential

Electric Potential

M A
V(r)=14πε0qrV(r) = \frac{1}{4\pi\varepsilon_0} \frac{q}{r}
Parameters & Definitions

VV is electric potential, qq is charge, and rr is separation distance.

Potential of a point charge in electrostatic space.

Potential Energy of Charge Systems

Electric Potential Energy

M A
U=14πε0q1q2rU = \frac{1}{4\pi\varepsilon_0} \frac{q_1 q_2}{r}
Parameters & Definitions

UU is electrostatic potential energy, q1,q2q_1, q_2 are charges, and rr is separation distance.

Potential energy of a two-charge configuration.

Conductors & Dielectrics

Induced Charge on a Dielectric Slab

M A
qp=q(11K)q_p = q \left( 1 - \frac{1}{K} \right)
Parameters & Definitions

qpq_p is the induced (polarization) charge, qq is the free charge on the capacitor plates, and KK is the dielectric constant of the slab.

Formula for the induced charge appearing on the faces of a dielectric slab placed in an external electric field.

Capacitors & Parallel Plates

Capacitance of Parallel Plate Capacitors

M A
C=Kε0AdC = \frac{K \varepsilon_0 A}{d}
Parameters & Definitions

CC is capacitance, KK is dielectric constant (K=1K=1 in vacuum), AA is plate area, and dd is separation.

Parallel plate capacitance (with dielectric KK).

Series & Parallel Capacitor Combinations

Series/Parallel Capacitance Formulas

M A
Cparallel=Ci1Cseries=1CiC_{parallel} = \sum C_i \quad \frac{1}{C_{series}} = \sum \frac{1}{C_i}
Parameters & Definitions

CparallelC_{parallel} is parallel equivalent capacitance, and CseriesC_{series} is series equivalent.

Combinations equivalent formulas.

Energy Stored in Capacitor

Stored Energy

M A
Ustored=12CV2=Q22CU_{stored} = \frac{1}{2} C V^2 = \frac{Q^2}{2C}
Parameters & Definitions

VV is voltage, QQ is charge, and UstoredU_{stored} is stored potential energy.

Energy stored in a capacitor.

19. Current Electricity

Drift Velocity & Current

Drift Velocity and Current

M A
vd=eEτmv_d = \frac{eE\tau}{m}
I=neAvdI = n e A v_d
Parameters & Definitions

vdv_d is drift velocity, ee is electronic charge, EE is electric field, τ\tau is relaxation time, mm is electron mass, II is current, nn is free charge density, and AA is area.

Microscopic model of current carrying conductors.

Ohm's Law & Resistance

Ohm's Law and Electrical Resistance

M A
V=IRV = I R
R=ρLAR = \rho \frac{L}{A}
Parameters & Definitions

VV is potential difference, II is current, RR is resistance, ρ\rho is electrical resistivity, LL is length, and AA is cross-sectional area.

Formulas for voltage-current relationship and the dependence of resistance on geometry and resistivity.

Temperature Dependence of Resistance

Temperature effect on Resistance

M A
R(T)=R0(1+αΔT)R(T) = R_0 (1 + \alpha \Delta T)
Parameters & Definitions

R(T)R(T) is final resistance, R0R_0 is initial resistance, α\alpha is temperature coefficient of resistance, and ΔT\Delta T is temperature change.

Effect of temperature on resistance values.

Internal Resistance & EMF

EMF and Internal Resistance

M A
V=EIrV = E - I r
Parameters & Definitions

VV is terminal voltage, EE is cell electromotive force (EMF), II is current, and rr is internal resistance.

Terminal potential difference of cells.

Cell Combinations

Equivalent EMF for Parallel Cells

M A
Eeq,parallel=Ei/ri1/riE_{eq,parallel} = \frac{\sum E_i/r_i}{\sum 1/r_i}
Parameters & Definitions

EiE_i and rir_i are the EMF and internal resistance values of individual cells, and Eeq,parallelE_{eq,parallel} is equivalent EMF.

Equivalent values for parallel groups of cells.

Kirchhoff's Laws

Kirchhoff's Current and Voltage Laws

M A
Iin=Iout\sum I_{in} = \sum I_{out}
ΔV=0\sum \Delta V = 0
Parameters & Definitions

Iin,IoutI_{in}, I_{out} are currents entering/leaving junctions, and ΔV\Delta V represents potential differences around a closed loop.

Conservation rules for charge (junction law) and energy (loop law) in circuits.

Wheatstone & Metre Bridges

Balanced Wheatstone Bridge and Meter Bridge

M A
PQ=RS(Balanced Bridge)\frac{P}{Q} = \frac{R}{S} \quad \text{(Balanced Bridge)}
RS=l100l(Meter Bridge)\frac{R}{S} = \frac{l}{100-l} \quad \text{(Meter Bridge)}
Parameters & Definitions

P,Q,R,SP, Q, R, S are bridge resistances, and ll is the balance length in centimeters along the 1-meter wire.

Symmetry conditions for zero current in the central galvanometer of a Wheatstone bridge and its meter bridge application.

Galvanometer to Ammeter and Voltmeter Conversion

M A
S=IgRgIIg(Ammeter Shunt)S = \frac{I_g R_g}{I - I_g} \quad \text{(Ammeter Shunt)}
R=VIgRg(Voltmeter Series)R = \frac{V}{I_g} - R_g \quad \text{(Voltmeter Series)}
Parameters & Definitions

SS is parallel shunt resistance, RR is series multiplier resistance, RgR_g is galvanometer coil resistance, IgI_g is full-scale deflection current, II is ammeter range, and VV is voltmeter range.

Formulas to convert a basic galvanometer into a high-range ammeter or voltmeter.

Potentiometer

Potentiometer Equations

M A
E1E2=l1l2\frac{E_1}{E_2} = \frac{l_1}{l_2}
r=R(l1l21)r = R \left( \frac{l_1}{l_2} - 1 \right)
Parameters & Definitions

E1,E2E_1, E_2 are EMFs of cells, l1,l2l_1, l_2 are balancing lengths, rr is internal resistance, and RR is standard resistance box resistance.

Formulas to compare cell EMFs and measure internal resistance.

20. Moving Charges & Magnetism

Biot-Savart Law & Circular Loop

Biot-Savart Law and Circular Loop Field

M A
dB=μ04πI(dl×r)r3d\vec{B} = \frac{\mu_0}{4\pi} \frac{I (d\vec{l} \times \vec{r})}{r^3}
Baxis=μ0IR22(R2+x2)3/2B_{axis} = \frac{\mu_0 I R^2}{2(R^2 + x^2)^{3/2}}
Parameters & Definitions

dBd\vec{B} is differential magnetic field, μ0\mu_0 is vacuum permeability, II is current, dld\vec{l} is length vector, r\vec{r} is position vector, RR is circular loop radius, and xx is axial distance.

Magnetic field differential vector and field value on the axis of a circular loop.

Magnetic Field of Finite Wire and Circular Arc

M A
Bwire=μ0I4πd(sinϕ1+sinϕ2)B_{\text{wire}} = \frac{\mu_0 I}{4\pi d}(\sin\phi_1 + \sin\phi_2)
Barc=μ0I4πRθB_{\text{arc}} = \frac{\mu_0 I}{4\pi R}\theta
Parameters & Definitions

BB is magnetic field, II is current, dd is perpendicular distance, ϕ1,ϕ2\phi_1, \phi_2 are angles subtended by wire ends, RR is circular arc radius, and θ\theta is arc angle in radians.

Magnetic fields at a point due to a straight wire segment and at the center of a circular current arc.

Ampere's Law & Solenoid Field

Ampere's Circuital Law and Straight Wire Field

M A
Bdl=μ0Ien\oint \vec{B} \cdot d\vec{l} = \mu_0 I_{en}
Bwire=μ0I2πrB_{wire} = \frac{\mu_0 I}{2\pi r}
Parameters & Definitions

IenI_{en} is enclosed net current, BwireB_{wire} is magnetic field strength at distance rr from wire, and dld\vec{l} is differential length.

Line integral relation for magnetic fields and field due to a long straight current conductor.

Lorentz Force & Orbit Radius

Lorentz Force and Circular Orbit Radius

M A
F=q(E+v×B)\vec{F} = q \left( \vec{E} + \vec{v} \times \vec{B} \right)
rorbit=mvqBr_{orbit} = \frac{m v}{q B}
Parameters & Definitions

F\vec{F} is Lorentz force, qq is charge, E\vec{E} is electric field, v\vec{v} is velocity, B\vec{B} is magnetic field, rorbitr_{orbit} is radius of orbit, and mm is mass of charge.

Force vector on moving charges and orbital parameters in uniform magnetic fields.

Forces on Current Wires

Magnetic Force on Current Wire

M A
F=I(L×B)\vec{F} = I (\vec{L} \times \vec{B})
Parameters & Definitions

II is current, L\vec{L} is wire length vector, and B\vec{B} is field vector.

Force vector on a current-carrying wire.

Force between Parallel Current Wires

Force per Unit Length between Parallel Wires

M A
FL=μ0I1I22πd\frac{F}{L} = \frac{\mu_0 I_1 I_2}{2\pi d}
Parameters & Definitions

I1,I2I_1, I_2 are currents, dd is separation distance, and F/LF/L is force per unit length.

Force per unit length between two parallel wires.

Loop Torque & Galvanometer Sensitivities

Torque on Loop, Galvanometer sensitivities

M A
τ=M×B\vec{\tau} = \vec{M} \times \vec{B}
Isens=θI=NBACI_{sens} = \frac{\theta}{I} = \frac{NBA}{C}
Vsens=θV=NBACRgV_{sens} = \frac{\theta}{V} = \frac{NBA}{C R_g}
Parameters & Definitions

τ\vec{\tau} is torque, M\vec{M} is magnetic dipole moment, B\vec{B} is field, NN is turn count, AA is area, CC is torsional restoring constant, and RgR_g is galvanometer coil resistance.

Torque vector on current loop and equations for galvanometer sensitivities.

21. Magnetism & Matter

Dipole Moments & Revolving Electron

Magnetic Moment of a Revolving Electron

M A
Melectron=evr2=e2mLM_{electron} = \frac{e v r}{2} = \frac{e}{2m} L
Parameters & Definitions

MelectronM_{electron} is magnetic moment, ee is electronic charge, vv is orbital speed, rr is orbital radius, mm is electron mass, and LL is orbital angular momentum.

Orbital magnetic dipole moment (Bohr Magneton) of a revolving hydrogenic electron.

Bar Magnet & Field Lines

Magnetic Field of a Bar Magnet

M A
Baxial=μ04π2Mr3B_{\text{axial}} = \frac{\mu_0}{4\pi} \frac{2M}{r^3}
Bequatorial=μ04πMr3B_{\text{equatorial}} = \frac{\mu_0}{4\pi} \frac{M}{r^3}
Parameters & Definitions

BB is the magnetic field, MM is the magnetic dipole moment, rr is the distance from the magnet center (rr \gg magnet length), and μ0\mu_0 is the permeability of free space.

Magnetic field formulas at axial and equatorial points of a short bar magnet.

Magnetic Materials

Magnetic Susceptibility and Curie's Law

M A
μr=1+χm\mu_r = 1 + \chi_m
χm=CT(Curie’s Law)\chi_m = \frac{C}{T} \quad \text{(Curie's Law)}
Parameters & Definitions

μr\mu_r is relative magnetic permeability, χm\chi_m is magnetic susceptibility, CC is Curie's constant, and TT is temperature in Kelvin.

Formula for relative permeability and Curie's temperature dependence of paramagnetic susceptibility.

22. Electromagnetic Induction

Faraday & Lenz Laws of Induction

Faraday's and Lenz's Law of Induction

M A
E=dΦBdt\mathcal{E} = -\frac{d\Phi_B}{dt}
ΦB=BdA\Phi_B = \int \vec{B} \cdot d\vec{A}
Parameters & Definitions

E\mathcal{E} is induced EMF, ΦB\Phi_B is magnetic flux, and B\vec{B} is magnetic field vector.

Mathematical expression relating induced EMF to time rate of change of magnetic flux.

Self & Mutual Inductance

Self and Mutual Inductance Definition

M A
ΦB=LI    Es=LdIdt\Phi_B = L I \implies \mathcal{E}_s = -L \frac{dI}{dt}
Φ12=MI2    E1=MdI2dt\Phi_{12} = M I_2 \implies \mathcal{E}_1 = -M \frac{dI_2}{dt}
Parameters & Definitions

LL is self-inductance coefficient, MM is mutual inductance coefficient, I,I2I, I_2 are currents, and Es,E1\mathcal{E}_s, \mathcal{E}_1 are induced EMFs.

Relationships linking magnetic flux linkage to current through coils.

23. Alternating Current

AC RMS & Peak Values

Peak and RMS values of AC

M A
Irms=I02I_{rms} = \frac{I_0}{\sqrt{2}}
Vrms=V02V_{rms} = \frac{V_0}{\sqrt{2}}
Parameters & Definitions

Irms,VrmsI_{rms}, V_{rms} are RMS current and voltage, and I0,V0I_0, V_0 are peak values.

Formulas calculating Root Mean Square values for sinusoidal AC.

Reactance & LCR Circuit Impedance

Impedance in LCR Series Circuits

M A
Z=R2+(XLXC)2Z = \sqrt{R^2 + (X_L - X_C)^2}
Parameters & Definitions

ZZ is impedance, RR is resistance, XL=ωLX_L = \omega L is inductive reactance, and XC=1/(ωC)X_C = 1/(\omega C) is capacitive reactance.

Impedance magnitude of LCR series circuits.

Resonance & Q-Factor

Resonant Frequency and Q-Factor

M A
ω0=1LC\omega_0 = \frac{1}{\sqrt{LC}}
Q=ω0LR=1RLCQ = \frac{\omega_0 L}{R} = \frac{1}{R}\sqrt{\frac{L}{C}}
Parameters & Definitions

ω0\omega_0 is resonant angular frequency, QQ is quality factor, LL is inductance, CC is capacitance, and RR is resistance.

Resonant frequency and Q-factor of LCR series circuits.

AC Power & Wattless Current

Average Power and Power Factor in AC

M A
Pavg=VrmsIrmscosϕP_{avg} = V_{rms} I_{rms} \cos\phi
cosϕ=RZ\cos\phi = \frac{R}{Z}
Parameters & Definitions

PavgP_{avg} is average power, cosϕ\cos\phi is power factor, and ϕ\phi is the phase difference between current and voltage.

Expression for average active power dissipation in AC circuits.

Transformers & AC Generators

Transformer Voltage and Current Relations

M A
VsVp=NsNp=IpIs\frac{V_s}{V_p} = \frac{N_s}{N_p} = \frac{I_p}{I_s}
Parameters & Definitions

Vp,VsV_p, V_s are primary/secondary voltages, Np,NsN_p, N_s are primary/secondary turns, and Ip,IsI_p, I_s are primary/secondary currents.

Voltage ratio and current ratio based on turns ratio in ideal transformers.

24. EM Waves

Displacement Current

Maxwell's Displacement Current

M A
Id=ε0dΦEdtI_d = \varepsilon_0 \frac{d\Phi_E}{dt}
Parameters & Definitions

IdI_d is displacement current, ε0\varepsilon_0 is vacuum permittivity, and ΦE\Phi_E is electric flux.

Current defined in terms of time rate of change of electric flux.

Electromagnetic Spectrum & Uses

Velocity of Light and Fields Ratio

M A
c=E0B0=1μ0ε0c = \frac{E_0}{B_0} = \frac{1}{\sqrt{\mu_0 \varepsilon_0}}
Parameters & Definitions

cc is speed of light, E0E_0 is electric field amplitude, B0B_0 is magnetic field amplitude, μ0\mu_0 is permeability of free space, and ε0\varepsilon_0 is permittivity of free space.

Relationship relating the speed of electromagnetic waves in a vacuum to the ratio of electric and magnetic field amplitudes, and vacuum constants.

25. Ray Optics

Spherical Mirrors & Mirror Formula

Mirror Formula

M A
1v+1u=1f\frac{1}{v} + \frac{1}{u} = \frac{1}{f}
Parameters & Definitions

u,vu, v are object/image distances, and ff is mirror focal length.

Fundamental equations describing reflection in spherical mirrors.

Refraction, Snell's Law & TIR

Snell's Law and Critical Angle

M A
n1sinθ1=n2sinθ2n_1 \sin\theta_1 = n_2 \sin\theta_2
sinθc=nrarendense\sin\theta_c = \frac{n_{rare}}{n_{dense}}
Parameters & Definitions

θ1,θ2\theta_1, \theta_2 are angles, n1,n2n_1, n_2 are refractive indices, and θc\theta_c is critical angle.

Equations describing refraction and the limit of total internal reflection.

Refraction at Spherical Surfaces

Refraction at Spherical Surfaces and Lens Maker's Formula

M A
μ2vμ1u=μ2μ1R\frac{\mu_2}{v} - \frac{\mu_1}{u} = \frac{\mu_2 - \mu_1}{R}
1f=(μlensμmedium1)(1R11R2)\frac{1}{f} = \left(\frac{\mu_{\text{lens}}}{\mu_{\text{medium}}} - 1\right) \left( \frac{1}{R_1} - \frac{1}{R_2} \right)
Parameters & Definitions

uu is object distance, vv is image distance, μi\mu_i are refractive indices, RiR_i are curvature radii, and ff is focal length.

Refraction relation at a single curved boundary and the formula to determine the focal length of a thin lens.

Thin Lenses & Lensmaker Formula

Lens Equations

M A
1v1u=1f\frac{1}{v} - \frac{1}{u} = \frac{1}{f}
1f=(nlensnmed1)(1R11R2)\frac{1}{f} = \left( \frac{n_{lens}}{n_{med}} - 1 \right) \left( \frac{1}{R_1} - \frac{1}{R_2} \right)
Parameters & Definitions

u,vu, v are object/image distances, ff is focal length, R1,R2R_1, R_2 are spherical radii, and nn represents refractive indices.

Thin lens formula and lensmaker's equation.

Refraction through Prism

Prism Formula

M A
nprism=sin(A+δm2)sin(A2)n_{prism} = \frac{\sin\left( \frac{A + \delta_m}{2} \right)}{\sin\left( \frac{A}{2} \right)}
Parameters & Definitions

nprismn_{prism} is the refractive index, AA is prism apex angle, and δm\delta_m is minimum deviation angle.

Refractive index formula for a prism at minimum deviation.

Optical Instruments

Magnification of Microscope and Telescope

M A
mmicroscope=Lfo(1+Dfe)m_{\text{microscope}} = -\frac{L}{f_o} \left( 1 + \frac{D}{f_e} \right)
mtelescope=fofem_{\text{telescope}} = -\frac{f_o}{f_e}
Parameters & Definitions

fof_o and fef_e are focal lengths of objective and eyepiece respectively, LL is tube length, and D=25D = 25 cm is the least distance of distinct vision.

Magnifying power formulas for compound microscope and astronomical telescope at normal adjustment.

26. Wave Optics

Wavefront & Huygens' Principle

Relation Between Phase and Path Difference

M A
Δϕ=2πλΔx\Delta \phi = \frac{2\pi}{\lambda} \Delta x
Parameters & Definitions

Δϕ\Delta \phi is phase difference, Δx\Delta x is path difference, and λ\lambda is wavelength of light.

Converts spatial path difference of coherent waves into their temporal phase difference.

Interference & YDSE

Interference Intensities and Fringe Width in YDSE

M A
Ires=I1+I2+2I1I2cosϕI_{res} = I_1 + I_2 + 2\sqrt{I_1 I_2}\cos\phi
βfringe=λDd\beta_{fringe} = \frac{\lambda D}{d}
Parameters & Definitions

IresI_{res} is resulting intensity, I1,I2I_1, I_2 are slit source intensities, ϕ\phi is phase difference, βfringe\beta_{fringe} is fringe width, λ\lambda is wavelength, DD is slit-screen distance, and dd is slit separation distance.

Mathematical description of resulting intensity and bright/dark fringe width in Young's Double Slit Experiment.

Single Slit Diffraction

Central Maximum Width

M A
wlinear=2λDaw_{linear} = \frac{2\lambda D}{a}
Parameters & Definitions

wlinearw_{linear} is linear width of central maximum, aa is slit width, and DD is distance to screen.

Formula for angular/linear width of central maximum in single slit diffraction.

Polarisation & Brewster Law

Brewster's Law

M A
n=tanipn = \tan i_p
Parameters & Definitions

nn is refractive index of medium, and ipi_p is polarizing angle (Brewster's angle).

Brewster's polarization angle for reflecting surfaces.

Resolving Power

Resolving Power of Microscope and Telescope

M A
Resolving Power of Microscope=2μsinθ1.22λ\text{Resolving Power of Microscope} = \frac{2\mu \sin\theta}{1.22 \lambda}
Resolving Power of Telescope=D1.22λ\text{Resolving Power of Telescope} = \frac{D}{1.22\lambda}
Parameters & Definitions

μ\mu is the refractive index of the medium between the object and the objective, θ\theta is the semi-vertical angle of the cone of light, λ\lambda is the wavelength, and DD is the diameter of the objective lens (aperture).

Formulas for the limit of resolution and resolving power of optical instruments.

27. Dual Nature

Einstein's Photoelectric Equation

Einstein's Photoelectric Equation

M A
Kmax=hνϕ=eV0K_{max} = h\nu - \phi = eV_0
Parameters & Definitions

KmaxK_{max} is maximum kinetic energy of electrons, hνh\nu is incident light energy, ϕ\phi is material work function, ee is electronic charge, and V0V_0 is stopping potential.

Relation between incident photon energy, work function, and maximum kinetic energy of emitted photoelectrons.

de Broglie Wavelength

de Broglie Wavelength of Matter Waves

M A
λ=hp=h2mK=h2mqV\lambda = \frac{h}{p} = \frac{h}{\sqrt{2mK}} = \frac{h}{\sqrt{2mqV}}
Parameters & Definitions

λ\lambda is de Broglie wavelength, hh is Planck's constant, pp is momentum, mm is mass, KK is kinetic energy, qq is charge, and VV is accelerating potential.

Wavelength associated with a moving particle of momentum pp or kinetic energy KK.

28. Atoms

Rutherford Model

Distance of Closest Approach

M A
r0=14πϵ02Ze2Kαr_0 = \frac{1}{4\pi\epsilon_0} \frac{2 Z e^2}{K_\alpha}
Parameters & Definitions

r0r_0 is the distance of closest approach, ZZ is the atomic number of the target nucleus, ee is elementary charge, KαK_\alpha is kinetic energy of the incoming alpha particle.

Formula to find the minimum distance an alpha particle reaches before being repelled by a nucleus.

Bohr Model & Energy Levels

Bohr Model Radii and Energy Levels

M A
rn=a0n2Z0.529n2Z A˚r_n = a_0 \frac{n^2}{Z} \approx 0.529 \frac{n^2}{Z} \text{ \AA}
En=E0Z2n213.6Z2n2 eVE_n = -E_0 \frac{Z^2}{n^2} \approx -13.6 \frac{Z^2}{n^2} \text{ eV}
1λ=RZ2(1n121n22)\frac{1}{\lambda} = R Z^2 \left( \frac{1}{n_1^2} - \frac{1}{n_2^2} \right)
Parameters & Definitions

rnr_n is the nn-th orbit radius, a0a_0 is Bohr radius, EnE_n is nn-th level energy, ZZ is atomic number, n,n1,n2n, n_1, n_2 are principal quantum numbers, and RR is Rydberg constant.

Quantized orbit radius and energy levels of hydrogen-like atoms.

29. Nuclei

Nuclear Size & Density

Nuclear Radius and Mass Number Relation

M A
R=R0A1/3R = R_0 A^{1/3}
Parameters & Definitions

RR is nuclear radius, R01.2 fmR_0 \approx 1.2 \text{ fm}, and AA is mass number.

Empirical formula relating nuclear radius to mass number.

Mass Defect & Binding Energy

Mass Defect and Binding Energy

M A
Δm=(Zmp+(AZ)mn)Mnuc\Delta m = \left( Z m_p + (A-Z) m_n \right) - M_{nuc}
Eb=Δmc2E_b = \Delta m c^2
Parameters & Definitions

Δm\Delta m is mass defect, ZZ is proton count, AA is mass number, mp,mnm_p, m_n are proton/neutron masses, MnucM_{nuc} is nuclear mass, and EbE_b is binding energy.

Difference in mass of components and energy binding the nucleus together.

Nuclear Fission & Fusion

Nuclear Reaction Q-Value

M A
Q=(MreactantsMproducts)c2Q = (\sum M_{\text{reactants}} - \sum M_{\text{products}}) c^2
Parameters & Definitions

QQ is the reaction energy, MreactantsM_{\text{reactants}} is the total mass of the reactants, MproductsM_{\text{products}} is the total mass of the products, and cc is the speed of light.

The amount of energy released or absorbed during a nuclear fission or fusion reaction.

Radioactive Decay Laws

Radioactive Decay Law and Half-Life

A
N(t)=N0eλtN(t) = N_0 e^{-\lambda t}
T1/2=ln2λ0.693λT_{1/2} = \frac{\ln 2}{\lambda} \approx \frac{0.693}{\lambda}
τmean=1λ\tau_{mean} = \frac{1}{\lambda}
Parameters & Definitions

N(t)N(t) is remaining active nuclei at time tt, N0N_0 is initial count, λ\lambda is decay constant, T1/2T_{1/2} is half-life, and τmean\tau_{mean} is mean life.

Equations describing exponential decay rate and half-life duration of radioactive elements.

30. Semiconductors

Energy Bands in Solids

Bandgap Energy

M A
Eg=hcλE_g = \frac{hc}{\lambda}
Parameters & Definitions

EgE_g is the bandgap energy, hh is Planck's constant, cc is the speed of light, and λ\lambda is the photon wavelength.

Energy difference between the valence band and conduction band, which determines the optical properties of semiconductors.

Intrinsic & Extrinsic Carrier concentration

Law of Mass Action in Semiconductors

M
nenh=ni2n_e n_h = n_i^2
Parameters & Definitions

nen_e is free electron density, nhn_h is hole density, and nin_i is intrinsic carrier concentration.

Thermal equilibrium concentration product relation for electrons and holes.

Semiconductor Diodes & Rectifiers

Maximum Efficiency of Half-Wave and Full-Wave Rectifiers

M
ηhalf=40.6%1+Rf/RL\eta_{\text{half}} = \frac{40.6\%}{1 + R_f/R_L}
ηfull=81.2%1+Rf/RL\eta_{\text{full}} = \frac{81.2\%}{1 + R_f/R_L}
Parameters & Definitions

η\eta is rectifier efficiency, RfR_f is forward diode resistance, and RLR_L is load resistance.

Maximum theoretical conversion efficiency of AC power to DC power for half-wave and full-wave rectifiers.

Zener Diode as Voltage Regulator

Zener Diode as a Shunt Voltage Regulator

M
IS=IZ+ILI_S = I_Z + I_L
IS=VinVZRSIL=VZRLI_S = \frac{V_{\text{in}} - V_Z}{R_S} \quad I_L = \frac{V_Z}{R_L}
Parameters & Definitions

IS,IZ,ILI_S, I_Z, I_L are series, Zener, and load currents; VinV_{\text{in}} is input voltage, VZV_Z is Zener breakdown voltage, RSR_S is series resistance, and RLR_L is load resistance.

Circuit equations calculating series resistor and Zener currents to maintain constant load voltage.

Special Purpose Diodes & Logic Gates

Boolean Logic Gate Outputs

M
YAND=ABYOR=A+BY_{\text{AND}} = A \cdot B \quad Y_{\text{OR}} = A + B
YNAND=ABYNOR=A+BY_{\text{NAND}} = \overline{A \cdot B} \quad Y_{\text{NOR}} = \overline{A + B}
Parameters & Definitions

A,BA, B are binary inputs (0 or 1), and YY is the output.

Mathematical outputs for basic logic gates (AND, OR, NAND, NOR).

31. Practical Physics

Vernier Calliper & Screw Gauge Least Count

Least Count of Vernier Calliper and Screw Gauge

M A
LCVernier=1 MSD1 VSDLC_{Vernier} = 1\text{ MSD} - 1\text{ VSD}
LCGauge=PitchNumber of Circular Scale DivisionsLC_{Gauge} = \frac{\text{Pitch}}{\text{Number of Circular Scale Divisions}}
Parameters & Definitions

LC represents Least Count, MSD represents Main Scale Division, VSD represents Vernier Scale Division, and Pitch is the linear advancement per full rotation of the screw gauge thimble.

Expressions defining the limits of measurement resolution for callipers and gauges.